Materials Data on Sr2YFeCu2O7 by Materials Project
Sr2YFeCu2O7 crystallizes in the orthorhombic Pmmm space group. The structure is three-dimensional. Sr2+ is bonded in a distorted q6 geometry to ten O2- atoms. There are a spread of Sr–O bond distances ranging from 2.72–2.93 Å. Y3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.39 Å) and four longer (2.41 Å) Y–O bond lengths. Fe3+ is bonded in a square co-planar geometry to four O2- atoms. There is two shorter (1.88 Å) and two longer (1.94 Å) Fe–O bond length. Cu2+ is bonded to five O2- atoms to form corner-sharing CuO5 square pyramids. There are a spread of Cu–O bond distances ranging from 1.90–2.20 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Sr2+, one Fe3+, and one Cu2+ atom to form a mixture of distorted corner and edge-sharing OSr4FeCu octahedra. The corner-sharing octahedra tilt angles range from 0–13°. In the second O2- site, O2- is bonded in a 6-coordinate geometry to two equivalent Sr2+, two equivalent Y3+, and two equivalent Cu2+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sr2+, two equivalent Y3+, and two equivalent Cu2+ atoms. In the fourth O2- site, O2- is bonded in a distorted linear geometry to four equivalent Sr2+ and two equivalent Fe3+ atoms.